TY - GEN
T1 - Approximation algorithms for BalancedCC multiwinner rules
AU - Brill, Markus
AU - Faliszewski, Piotr
AU - Sommer, Frank
AU - Talmon, Nimrod
N1 - Publisher Copyright:
© 2019 International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - X-BalancedCC multiwinner voting rules constitute an attractive but computationally intractable compromise between the proportionality provided by the Monroe rule and the diversity provided by the Chamberlin-Courant rule. We show how to use the Greedy-Monroe algorithm to get improved approximation results for the X-BalancedCC rules and for the Chamberlin-Courant rule, by appropriately setting a "schedule" for the sizes of virtual districts. We describe a polynomial-time algorithm for computing a schedule that guarantees high approximation ratio, but show that finding the best possible schedule for a given election is NP-hard. We further evaluate our algorithms experimentally and show that they perform very well in practice.
AB - X-BalancedCC multiwinner voting rules constitute an attractive but computationally intractable compromise between the proportionality provided by the Monroe rule and the diversity provided by the Chamberlin-Courant rule. We show how to use the Greedy-Monroe algorithm to get improved approximation results for the X-BalancedCC rules and for the Chamberlin-Courant rule, by appropriately setting a "schedule" for the sizes of virtual districts. We describe a polynomial-time algorithm for computing a schedule that guarantees high approximation ratio, but show that finding the best possible schedule for a given election is NP-hard. We further evaluate our algorithms experimentally and show that they perform very well in practice.
KW - Approximation algorithms
KW - Chamberlin-Courant rule
KW - Greedy algorithms
KW - Monroe rule
KW - Multiwinner elections
UR - http://www.scopus.com/inward/record.url?scp=85077092276&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85077092276
T3 - Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS
SP - 494
EP - 502
BT - 18th International Conference on Autonomous Agents and Multiagent Systems, AAMAS 2019
PB - International Foundation for Autonomous Agents and Multiagent Systems (IFAAMAS)
T2 - 18th International Conference on Autonomous Agents and Multiagent Systems, AAMAS 2019
Y2 - 13 May 2019 through 17 May 2019
ER -